WASHINGTON (AP) -- A senior State Department official says his department never concluded that the consulate attack in Libya stemmed from protests over an American-made video ridiculing Islam, raising further questions about why the Obama administration initially used that explanation after assailants killed four Americans there.

Briefing reporters Tuesday, officials provided a more detailed rundown of the Sept. 11 attack in Benghazi. They said the attack came without warning and involved multiple groups of men armed with weapons such as machine guns and rocket-propelled grenades.

But asked about the administration's initial explanation linking the violence to the video, one official said, "That was not our conclusion." The official called it a question for "others" to answer.

The officials spoke on condition of anonymity because they weren't authorized to speak publicly on the matter.